A data offloading technology is a technology that service data is transmitted according to at least two transmission paths. The at least two transmission paths may be established by using different transmission resources or transmission networks of different standards.
An example in which service data is transmitted between an access network device and a terminal is used. Offloading transmission may be implemented on service data of a same service by using a licensed spectrum and an unlicensed spectrum, where the unlicensed spectrum is also referred to as a common spectrum, and any organization or person may use a current idle spectrum in the common spectrum by following a particular rule. Alternatively, offloading transmission may be implemented on service data of a same service by using a transmission resource provided by a base station and a transmission resource provided by a WLAN (Wireless Local Area Networks). Alternatively, offloading transmission may be implemented on service data of a same service by using a transmission resource provided by a primary eNodeB and a transmission resource provided by a secondary eNodeB.
In a process of implementing embodiments of the present invention, the inventor finds that the foregoing technology has at least the following problem: because the unlicensed spectrum exists dynamically, and deployment of the WLAN and the secondary eNodeB may be discontinuous, QoS (Quality of Service) in a transmission process cannot be ensured when data is offloaded by using the unlicensed spectrum, the WLAN, or the secondary eNodeB.